AVALIAÇÃO DA PREVALÊNCIA DE TALASSEMIA ALFA EM UMA POPULAÇÃO COM ANEMIA MICROCÍTICA E HIPOCRÔMICA.

Abstract

Among genetically determined diseases, hereditary anemias are the most common, and are frequent among the Brazilian population (WHO, 1982). This is because of the mixing of races that occurred since the begining of the Brazilian set up, disseminating genes that determine hemoglobin disorders (Naoum, 1997b). Alphathalassemia is a hereditary disease due to the deficient synthesis of the alpha chains, causing an excess of beta chains, which then form tetramers known as hemoglobin H (Bonini-Domingos et al, 2003). Major thalassemias can be ruled out easily, however minor thalassemias can be easily confused with anemia due to iron deficiency. Minor thalassemias do not respond to iron supplements because their cause is genetic (Cunningham & Rising, 1977). We have evaluated individuals with hypocromic microcytic anemia by using specific lab tests, in order to identify the possible hemoglobin disorders associated. We have evaluated 201 samples from 141 female and 60 male individuals, ranging from 1 to 65 years of age. We have applied the following lab tests: acid and alkaline hemoglobin electrophoresis, serum protein electrophoresis, osmotic resistance test to 0,36% saline, detection of hemoglobin H, sickling cell test and High Performance Liquid Chromatography (HPLC). Our results showed that 145 individuals (72%) had normal hemoglobin profile, while 56 individuals (27,9%) showed some hemoglobin abnormality. Twenty-seven out of 56 individuals (13,4%) showed alpha-thalassemia, 9 (4,5%) showed beta-thalassemia, 13 (6,6%) had sickle cell trait, 6 (3%) had hemoglobin C and only 1 had mixed features combining alpha-thalassemia and sickle cell trait. Hemoglobin diseases are of genetic causes and are universally distributed, and the World Health Organization (WHO), since 1982, is calling the attention so that the detection of the major forms of these diseases are diagnosed and treated. It is also recommended a demographic survey in order to determine the prevalence of hemoglobin disorders to identify sick individuals, as well as is to illustrate them about their problem (WHO, 1982). The results of these actions implicate in better quality of life and also provide enough knowledge so that individuals harboring hemoglobin disorders may plan their lives and avoid transmitting their phenotypes to their descendants (Naoum, 1987b). Therefore it becomes clear that hereditary anemias are a problem to public health and the genetic counseling must be done responsibly and by trained professionals to ensure that the final goal of a better quality of life to the patients and their relatives will be achieved.